1. Field
The present application relates to a motor having a rotor and a stator and, more particularly, to a rotor of a motor.
2. Background
Motors used for a transmission include an interior permanent magnet (IPM) motor, a surface permanent magnet (SPM) motor, and so on.
The IPM motor is a motor in which a magnet is buried in a rotor. The SPM motor is a motor in which a part of a magnet is disposed to be exposed through a surface of a rotor. A screw type of rotor may be used for the SPM motor.
The screw type of rotor generally includes a ball spindle that is a rotational shaft, a tube, a nut spindle that is installed in the tube so as to support the tube and is screwed onto the ball spindle, a core installed outside the tube so as to attach a magnet, and the magnet attached to the core.
In this way, many parts including the tube, the nut spindle, and the core are separately provided and assembled.
For this reason, processes of assembling these parts are required. As a result, a manufacturing process is complicated. Further, a tolerance is accumulated with assembly of each part, reducing overall precision.
The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background.